Messages in this thread Patch in this message | | | Date | Mon, 7 Apr 2003 08:27:59 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH][2.5] avoid scribbling in IDT with high interrupt count. |
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On Mon, 7 Apr 2003, Zwane Mwaikambo wrote: > > On systems with high interrupt counts we end up overshooting the > interrupt[] array and dumping garbage entry points into the idt. This > patch checks for out of bounds access during ioapic setup as well as > returning -ENOSPC when we run out of vectors to assign in > assign_irq_vector, thus allowing us to remove the panic and boot a 320 > interrupt source system with 2.5.66.
Zwane - is there any reason we couldn't just start re-using irq vector offsets when this happens? We already re-use the vectors themselves, so restarting the offset pointer shouldn't really _change_ anything.
In other words, I'm wondering if this simpler patch wouldn't be sufficient instead?
Can you please test this, and re-submit (and if you can explain why your patch is better, please do so - I have nothing fundamentally against it, I just want to understand _why_ the complexity is needed).
Thanks,
Linus
--- 1.58/arch/i386/kernel/io_apic.c Thu Mar 20 03:11:41 2003 +++ edited/arch/i386/kernel/io_apic.c Mon Apr 7 08:25:48 2003 @@ -1110,12 +1110,9 @@ goto next; if (current_vector > FIRST_SYSTEM_VECTOR) { - offset++; + offset = (offset+1) & 7; current_vector = FIRST_DEVICE_VECTOR + offset; } - - if (current_vector == FIRST_SYSTEM_VECTOR) - panic("ran out of interrupt sources!"); IO_APIC_VECTOR(irq) = current_vector; return current_vector; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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